Mercurinium Ion

Definition

The mercurinium ion is a reactive intermediate formed during the oxymercuration-demercuration reaction, a common method for the hydration of alkenes to form alcohols. It is a key species involved in the preparation of alcohols and ethers.

5 Must Know Facts For Your Next Test

1. The mercurinium ion is an electrophilic intermediate formed when an alkene reacts with a mercury(II) salt and water.
2. During the oxymercuration step, the mercurinium ion is stabilized by the solvent water, forming a haloalkylmercury(II) species.
3. The mercurinium ion is then reduced in the demercuration step, typically using sodium borohydride, to yield the final alcohol product.
4. Oxymercuration-demercuration is a useful method for the hydration of alkenes, as it proceeds with anti-Markovnikov regiochemistry.
5. The mercurinium ion intermediate is also involved in the preparation of ethers via the Williamson ether synthesis, where it reacts with an alkoxide nucleophile.

Review Questions

• Explain the role of the mercurinium ion in the oxymercuration-demercuration reaction for the hydration of alkenes.
  • The mercurinium ion is a key intermediate formed during the oxymercuration-demercuration reaction, which is a common method for the hydration of alkenes to form alcohols. In the first step, the alkene reacts with a mercury(II) salt and water to form the electrophilic mercurinium ion. This intermediate is stabilized by the solvent water, forming a haloalkylmercury(II) species. In the second step, the mercurinium ion is reduced, typically using sodium borohydride, to yield the final alcohol product. The mercurinium ion is essential for the anti-Markovnikov regiochemistry observed in this reaction.
• Describe how the mercurinium ion is involved in the preparation of alcohols and ethers.
  • The mercurinium ion is a crucial intermediate in the preparation of alcohols via the oxymercuration-demercuration reaction. In this two-step process, the mercurinium ion is first formed when an alkene reacts with a mercury(II) salt and water. The mercurinium ion is then reduced in the demercuration step to yield the final alcohol product. Additionally, the mercurinium ion is involved in the Williamson ether synthesis, where it reacts with an alkoxide nucleophile to form an ether. The reactivity of the mercurinium ion allows for the controlled formation of both alcohols and ethers, making it an important species in organic synthesis.
• Analyze the significance of the mercurinium ion in the context of the hydration of alkenes, the preparation of alcohols, and the synthesis of ethers.
  • The mercurinium ion is a central and versatile intermediate in organic chemistry, playing a crucial role in the hydration of alkenes, the preparation of alcohols, and the synthesis of ethers. During the oxymercuration-demercuration reaction, the mercurinium ion is formed when an alkene reacts with a mercury(II) salt and water, and it is then reduced to yield the final alcohol product. This reaction proceeds with anti-Markovnikov regiochemistry, which is facilitated by the mercurinium ion intermediate. Additionally, the reactivity of the mercurinium ion is exploited in the Williamson ether synthesis, where it can be intercepted by an alkoxide nucleophile to form an ether. The ability of the mercurinium ion to participate in these diverse transformations highlights its significance in organic synthesis and its importance as a key term in understanding the preparation of alcohols and ethers.

Related terms

Oxymercuration: A two-step reaction that involves the addition of water to an alkene, mediated by mercury(II) salts, to form an alcohol.

Demercuration: The second step of the oxymercuration-demercuration reaction, where the mercurinium ion intermediate is reduced to form the final alcohol product.

Hydration of Alkenes: The addition of water to an alkene, resulting in the formation of an alcohol.